[Objectives]To evaluate the effects of shell length and shucking of Ruditapes philippinarum on Scylla paramamosain.[Methods]Feeding different-sized mud crabs with shucked or unshelled R.philippinarum of various shell ...[Objectives]To evaluate the effects of shell length and shucking of Ruditapes philippinarum on Scylla paramamosain.[Methods]Feeding different-sized mud crabs with shucked or unshelled R.philippinarum of various shell lengths for 60 d,their growth performance and energy allocation patterns were evaluated.[Results]Survival rates were high across all treatments,with only sporadic mortality observed during the experiment.When fed unshelled clams,the weight gain rate and specific growth rate of smaller crabs were significantly higher than those of larger crabs,showing a clear decreasing trend with increasing initial body mass.Crabs with an initial mass of 3.86 g allocated significantly less energy to growth than those with an initial mass of 49.83 g.Crabs with an initial mass of 49.83 g had a significantly lower proportion of energy lost in molting than those with an initial mass of 260.41 g.Crabs with an initial mass of 3.86 g had a significantly higher proportion of energy lost in feces than those with initial masses of 182.48 and 260.41 g.No significant differences were found in the proportions of energy allocated to nitrogen excretion and metabolic consumption.When crabs within an initial mass range of 202.76-210.25 g were fed with clams of different shell lengths,no significant differences were observed in their growth performance or energy allocation indicators.Feeding shucked versus unshelled clams to crabs of different initial sizes resulted in significant differences in growth performance based on the crab s initial size,but the removal of clam shells had no significant effect.As the initial mass of the crabs increased,the proportion of energy lost through molting increased significantly,while the proportion lost in feces decreased significantly.However,whether the clams were removed or not had no significant impact on the crabs energy allocation indicators.[Conclusions]The initial body mass of the crabs significantly influences growth performance and energy allocation across different treatments,whereas clam shell length and shell removal have minor effects.展开更多
[Objectives]To study the utilization efficiency of different diets for juvenile Scylla paramamosain.[Methods]Low-value fish,shrimp,clam and clamworm were fed to overwintering young mud crabs,and the performance of the...[Objectives]To study the utilization efficiency of different diets for juvenile Scylla paramamosain.[Methods]Low-value fish,shrimp,clam and clamworm were fed to overwintering young mud crabs,and the performance of the feed was evaluated by growth,feed utilization and energy allocation.[Results]Shrimp-fed mud crabs showed the best growth performance,while fish-fed mud crabs showed the worst growth performance and converted the least protein and energy for growth.Shrimp-fed mud crabs molted more frequently,and the dry matter mass and energy of Exuviation were significantly higher than those of fish-fed mud crabs.The shrimp-fed crabs also had significantly higher food intake than those fish-fed crabs.The order of feed conversion efficiency(FCE)of fish-fed mud crabs was Polychaete>clam>shrimp>fish,while the order of FCE calculated with FCE-P and FCE-E was Polychaete>clam>shrimp>fish.Fish-fed mud crabs had the least energy intake and the least energy for growth,molting,excretion,metabolism,and feces.Among the four treatments,the mud crabs fed on Polychaete had the largest proportion of energy used for growth,while the mud crabs fed on fish had the largest proportion of energy used for molting.The proportion of energy consumed by mud crabs fed on Polychaete was the smallest,which may be the main reason for the higher FCE-P and FCE-E of mud crabs fed on Polychaete.[Conclusions]The results of this experiment showed that the utilization of low-value fish by mud crabs was the worst,suggesting that fish should not be used as control or reference food when studying the formula feed of mud crabs.展开更多
Dear Editor,In the＂big data era＂,the amount of digital information is growing explosively,therefore,a reliable data storage medium for large-scale digital archiving is urgently needed.However,the increase of existin...Dear Editor,In the＂big data era＂,the amount of digital information is growing explosively,therefore,a reliable data storage medium for large-scale digital archiving is urgently needed.However,the increase of existing storage capacity cannot keep up with the growth of digital information.Moreover,the durability of conventional storage teclanologles, sucn as magnetic and optical devices, is very limited. Since the first demonstration of using DNA to store messages in 1988, DNA has been considered as a promising data storage medium due to its high-density and long-term stability （half-life〉500years） （Allentoft et al., 2012）.展开更多
基金Supported by Guangxi Natural Science Foundation(2017GXNSFAA198022)Guangxi Key R&D Program(Guike AB16380105)+1 种基金Open Fund of Guangxi Key Laboratory of Marine Biodiversity Conservation(2023KA01)Doctoral Initiation Funding Project of Guangxi University of Chinese Medicine(2018BS034).
文摘[Objectives]To evaluate the effects of shell length and shucking of Ruditapes philippinarum on Scylla paramamosain.[Methods]Feeding different-sized mud crabs with shucked or unshelled R.philippinarum of various shell lengths for 60 d,their growth performance and energy allocation patterns were evaluated.[Results]Survival rates were high across all treatments,with only sporadic mortality observed during the experiment.When fed unshelled clams,the weight gain rate and specific growth rate of smaller crabs were significantly higher than those of larger crabs,showing a clear decreasing trend with increasing initial body mass.Crabs with an initial mass of 3.86 g allocated significantly less energy to growth than those with an initial mass of 49.83 g.Crabs with an initial mass of 49.83 g had a significantly lower proportion of energy lost in molting than those with an initial mass of 260.41 g.Crabs with an initial mass of 3.86 g had a significantly higher proportion of energy lost in feces than those with initial masses of 182.48 and 260.41 g.No significant differences were found in the proportions of energy allocated to nitrogen excretion and metabolic consumption.When crabs within an initial mass range of 202.76-210.25 g were fed with clams of different shell lengths,no significant differences were observed in their growth performance or energy allocation indicators.Feeding shucked versus unshelled clams to crabs of different initial sizes resulted in significant differences in growth performance based on the crab s initial size,but the removal of clam shells had no significant effect.As the initial mass of the crabs increased,the proportion of energy lost through molting increased significantly,while the proportion lost in feces decreased significantly.However,whether the clams were removed or not had no significant impact on the crabs energy allocation indicators.[Conclusions]The initial body mass of the crabs significantly influences growth performance and energy allocation across different treatments,whereas clam shell length and shell removal have minor effects.
基金Supported by Guangxi Natural Science Foundation(2017GXNSFAA198022)Guangxi Key R&D Program(Guike AB16380105)+1 种基金Open Fund of Guangxi Key Laboratory of Marine Biodiversity Conservation(2023KA01)Doctoral Initiation Funding Project of Guangxi University of Chinese Medicine(2018BS034).
文摘[Objectives]To study the utilization efficiency of different diets for juvenile Scylla paramamosain.[Methods]Low-value fish,shrimp,clam and clamworm were fed to overwintering young mud crabs,and the performance of the feed was evaluated by growth,feed utilization and energy allocation.[Results]Shrimp-fed mud crabs showed the best growth performance,while fish-fed mud crabs showed the worst growth performance and converted the least protein and energy for growth.Shrimp-fed mud crabs molted more frequently,and the dry matter mass and energy of Exuviation were significantly higher than those of fish-fed mud crabs.The shrimp-fed crabs also had significantly higher food intake than those fish-fed crabs.The order of feed conversion efficiency(FCE)of fish-fed mud crabs was Polychaete>clam>shrimp>fish,while the order of FCE calculated with FCE-P and FCE-E was Polychaete>clam>shrimp>fish.Fish-fed mud crabs had the least energy intake and the least energy for growth,molting,excretion,metabolism,and feces.Among the four treatments,the mud crabs fed on Polychaete had the largest proportion of energy used for growth,while the mud crabs fed on fish had the largest proportion of energy used for molting.The proportion of energy consumed by mud crabs fed on Polychaete was the smallest,which may be the main reason for the higher FCE-P and FCE-E of mud crabs fed on Polychaete.[Conclusions]The results of this experiment showed that the utilization of low-value fish by mud crabs was the worst,suggesting that fish should not be used as control or reference food when studying the formula feed of mud crabs.
基金supported by the Suzhou Science and Technology Project and Fund for Young Scientists of Science and Technology Program of Jiangsu
文摘Dear Editor,In the＂big data era＂,the amount of digital information is growing explosively,therefore,a reliable data storage medium for large-scale digital archiving is urgently needed.However,the increase of existing storage capacity cannot keep up with the growth of digital information.Moreover,the durability of conventional storage teclanologles, sucn as magnetic and optical devices, is very limited. Since the first demonstration of using DNA to store messages in 1988, DNA has been considered as a promising data storage medium due to its high-density and long-term stability （half-life〉500years） （Allentoft et al., 2012）.
